ELLIPSOMETRIC IMAGING OF SURFACE DROPS

We quantify the behavior of the real (R) and imaginary (I) components of the optical response of a recently developed ellipsometric microsco pe. For a polydimethylsiloxane drop spreading on top of a silicon wafe r substrate the experimental values of R and I show the same correlati on as a function of film thickness as do the theoretical values. This confirms that the ellipsometric microscope is operating as predicted. The ellipsometric microscope has a thickness resolution of similar to 0.1 nm and a lateral spatial resolution of similar to 1 mu m and can c ollect 512 x 512 pixels of information in approximately 20s. (C) 1996 Optical Society of America